Litter Storage and Water-holding Characteristics of Typical Forest Types in Ningxia

By using the methods of field investigation and soaking extraction,the storage,thickness,water-holding rate,water-absorption rate and interception of the litter in 10 forest types of Ningxia were studied,and changes of litter water-holding characteristics among different regions of the same vegetation also included.The results show that the amount of litters was 1.06~76.49 t/hm2,with a rank of conifer forest broadleaved forest(except Quercus wutaishanica forest).The maximum water-holding rate of the un-decomposed layer ranged from 117.82% to 208.05%,and the half-decomposed layer ranged from 169.34% to 302.85%.These two parameters both increased with soaking time,following a logarithmic curve.The water-holding rate data of Picea crassifolia analysis revealed that there was no obvious difference in three places around Ningxia province,but the case of Populus simonii forest was opposite.Both Larix principis-rupprechtii and Pinus tabuliformis forest follow the law that the un-decomposed layer had a significant change while the half-decomposed layer show slight difference.And the water-absorption rate of both layers reached the maximum value in the first half an hour,slowed down obviously then.The modified interception ranged from 0.11~10.27 mm,followed the order of conifer forest broadleaved forest.